The present invention relates to bandages for wounds, and more particularly to the provision of bandages for use with a vacuum source.
The prior art contemplates that chronic wounds may be treated by providing a vacuum in the space above the wound to promote healing. A number of prior art references teach the value of the vacuum bandage or the provision of the vacuum in the space above the surface of a chronic wound.
A vacuum bandage is a bandage having a cover which seals about the outer perimeter of the wound and under which a vacuum is established to act on the wound surface. This vacuum applied to the wound surface causes healing of chronic wounds. Typically, suction tubes are provided for drawing away exudate from the wound, and this suction may be used to create the vacuum under the cover. If the cover is a flexible cover, which is typically more comfortable for the patient, some sort of porous packing may be provided under the cover to provide the space in which the vacuum is formed. The following U.S. Patents establish the nature of vacuum treatment bandages and devices: U.S. Pat. Nos. 6,095,992, 6,080,189, 6,071,304, 5,645,081, 5,636,643, 5,358,494, 5,298,015, 4,969,880, 4,655,754, 4,569,674, 4,382,441, and 4,112,947. All of such references are incorporated herein by reference for purposes of disclosing the nature of such vacuum treatment of wounds.
As shown, for example, in U.S. Pat. No. 5,645,081 (hereinafter the '081 patent), a method of treating tissue damage is provided by applying negative pressure to a wound. The negative pressure is provided in sufficient duration and magnitude to promote tissue migration in order to facilitate the closure of the wound. FIG. 1 of the '081 patent discloses an open cell polyester foam section covering the wound, a flexible hollow tube inserted into the foam section at one end and attached to a vacuum pump at another end, an adhesive sheet overlying the foam section and tubing to adhere to the skin surrounding the wound in order to form a seal that allows the creation of a vacuum when the suction pump is operating. The '081 patent further teaches use of negative pressure between about 0.1 and 0.99 atmospheres, and that the pressure can be substantially continuous, wherein the pressure is relieved only to change the dressing on the wound. Alternatively, the '081 patent teaches use of a cyclic application of pressure in alternating periods of application and non-application. In a preferred embodiment, pressure is applied in 5 minute periods of application and non-application.    Various other prior art references teach the value of the vacuum bandage or the provision of vacuum to the surface of a chronic wound. Several Russian language articles exist which establish the efficacy of vacuum therapy discovered in the 1980's. Examples of such prior art articles, each of which discusses the use of application of vacuum to a wound to promote healing, are as follows: “Vacuum therapy in the treatment of acute suppurative diseases of soft tissues and suppurative wounds”, Davydov, et al., Vestn, Khir., September 1988 (the September 1988 article); “Pathenogenic mechanism of the effect of vacuum therapy on the course of the wound process”, Davydov, et al. Khirurigiia, June 1990 (the June 1990 article); and “Vacuum therapy in the treatment of suppurative lactation mastitis”, Davydov, et al. Vestn. Khir., November 1986 (the November 1986 article).
The Russian articles distinguish wound drainage from the use of vacuum therapy for healing. The Russian authors report that vacuum therapy resulted in faster cleansing of the wound and more rapid detoxification than with the traditional incision-drainage method. The November 1986 Russian article describes the vacuum therapy techniques as a reduction of 0.8-1 atmosphere for 20 minutes at the time of surgery, and subsequent 1.5 to 3 hour treatments at a reduced pressure of 0.1 to 0.15 from atmosphere, twice daily. These Russian articles teach the use of negative pressure to effect healing. The articles describe using several sessions per day, each lasting up to one hour, with a vacuum of 76-114 mmHg. The Russian articles teach using this vacuum method to decrease the number of microbes in the wound. The June 1990 article teaches that this vacuum therapy provides a significant antibacterial effect. The article describes the stepped up inflow of blood to the zone around the wound to lead to an increase in the number of leukocytes reaching the focus of inflammation. Subsequent articles and patents further develop the benefits obtained with vacuum therapy. The prior art, therefore, teaches the benefit and value of a vacuum bandage.
According to the present disclosure, a thin, flexible member for use in a vacuum bandage is provided. The member includes a wound contacting surface configured to be in contact with and conform to a wound surface of a wound. The member further includes a plurality of discrete holes formed in the wound contacting surface, a port which communicates with the vacuum source, and communicating means between the holes and the port. The member is made from a generally non-compressible material. Further, the material is generally transparent and non-porous.
In some illustrative embodiments, the communicating means comprises a plurality of distinct passageways between each hole and the port. The member includes a wound contacting layer having channels formed therein and a cover coupled to the wound contacting layer. The cover cooperates with the wound contacting layer, and the channels formed therein, to define the passageways. The member further includes a boss positioned near the port of the cover to prevent an upper surface of the wound contacting layer from sealing off the port of the cover when vacuum is applied to the port.
In some illustrative embodiments, the wound contacting surface of the member includes spacers contacting the wound to define a suction space between the member and the wound surface. The wound contacting surface may also be textured or roughened for contact with the wound surface. The unevenness of the textured or roughened surface provides communication of the negative pressure across the wound surface.
In some embodiments, the spacers and suction space are defined by a plurality of channels formed in the wound contacting surface. Each of the channels formed in the wound contacting surface opens toward the wound surface and includes side edges contacting the wound.
In some embodiments of the invention, the dressing member has such a plurality of channels formed in patterns on both of the wound contacting surface and the opposite surface and the plurality of holes provide communication between the channels on both surfaces. In some embodiments, the channel patterns on both surfaces are congruent or superimposed with both patterns radiating outwardly from the port and with the holes spaced radially along the channels.
In some embodiments, the dressing member is made from a material which is to be trimmed conformingly to fit the wound. In some embodiments, the dressing member is relatively transparent such that the condition of the wound surface can be observed through the wound member.
There is provided, therefore, a dressing for a wound, the dressing comprising a relatively thin flexible member which can be trimmed conformingly to fit the wound surface. A suction and irrigation port is associated with the dressing member, and a plurality of channels or passageways is formed in the member leading away from the port to provide communication between the port and areas of the wound surface. The dressing member is provided with a plurality of through holes in communication with the channels. A packing may be placed over the flexible member and a sealing film may be placed over the packing to seal around the perimeter of the wound to provide an enclosed space above the member in which a vacuum is formed by suction on the port. It will be appreciated, however, that some caregivers may choose to leave packing out of the bandage and have the sealing film placed directly over the flexible member. It has been found that some bandages function quite well without packing. Also, visual observation is improved without the packing. Irrigation fluid may be introduced to the port to impinge upon the wound surface and this fluid and wound exudate is removed from the space between the wound and the bandage member by suction applied to the port. It will be appreciated that the vacuum therapy and the irrigation therapy may take place without removal of the bandage. The illustrative member with the downwardly opening channels or spacers on the wound contacting surfaces provides a suction space which will uniformly apply the vacuum and the irrigation to the surface of the wound bed.
The covered channels on the opposite surface and the holes through the member further contribute to the ability to uniformly apply the vacuum therapy and irrigation fluid to the wound surface. A relatively large portion of the wound surface will be exposed to the vacuum therapy and irrigation using the illustrative bandage member. A large number of redundant passageways are provided for communicating from the access port directly to the wound surface. While some of the passageways may become blocked by exudate particles from the wound surface, other passageways will remain open for suction and irrigation.
The illustrative bandage, therefore, provides a relatively thin, flexible, comfortable bandage member which can be trimmed generally conformingly to fit into a wound bed and apply vacuum therapy and irrigation uniformly to the wound surface. The illustrative covered channel passageways on the opposite (upper or outer) surface provide a multitude of clearly defined passageways leading from the access port to the through holes leading directly into the suction space under the member.
In further embodiments, the member includes a connecter coupled to the cover for communication with the port of the cover. The connecter is configured for communication with the vacuum source and defines a right-angled passageway to provide a horizontal tube attachment.
In yet another embodiment, the member further includes an outer adhesive perimeter. This perimeter is configured to seal about the wound to a patient's healthy skin surrounding the wound. In another embodiment, the member further includes a wire form to permit a user or caregiver to mold or shape the member to fit the particular shape of a wound. In one embodiment, the wire form is molded into the cover and in another embodiment the wire form is molded into the wound contacting layer.
In still another embodiment, the member further includes a plurality of irrigation passageways configured for communication with an irrigation source and with the wound surface. The irrigation passageways are distinct from the passageways described above which are configured for communication with the vacuum source. The member further includes an irrigation port in communication with the irrigation passageways and configured for communication with the irrigation source. An irrigation layer is provided and includes channels formed therein which define the irrigation passageways.
A wound bandage for use on a chronic wound located on a patient's heel is also disclosed. In this embodiment, the member is saddle-shaped and includes an upper portion, a lower portion, and a neck portion coupled to and positioned between the upper portion and the lower portion. The saddle-shaped member is foldable into a configuration that cups the patient's heel. An embodiment having a member with a generally “V-shaped” cross-section is provided for use with sternal or abdominal wounds. The V-shaped member includes a right wing and a left wing coupled to the right wing. Further, the V-shaped member includes a central passageway in communication with the port of the cover and a plurality of lateral passageways in communication with the central passageway.
Another alternative member is disclosed for use with tunneled wounds. This member includes a truncated cone-shaped portion, a tube-shaped portion coupled to the cone-shaped portion, and a dome-shaped portion coupled to the tube-shaped portion. The port is positioned in the cone-shaped portion. Yet another member is disclosed which is dome-shaped and has a convex wound contacting surface.
A method of forming a member of a wound bandage is further provided in accordance with the present disclosure. The method includes the steps of molding a cover from a semi-cured silicone and the step of heat-sealing the cover to a wound contacting layer. In illustrative embodiments, the method further includes providing a connecter and heat sealing the connecter to the cover. In further embodiments, the method includes molding the connecter and the wound contacting layer from fully-cured silicone.
Additionally, a method of treating an open wound having a wound surface is provided in accordance with the present disclosure. The method includes the steps of providing a flexible member fabricated from non-porous material to have a wound contacting surface with holes in the surface, a port configured to communicate with a vacuum source, and passageways providing communication between the holes and the port. The method further includes placing the member into contact with the wound to functionally and physically interface with the wound surface and connecting the port to a vacuum source to provide suction at each of the holes. In illustrative embodiments, the method further includes the step of covering the wound and the member adjacent the wound to provide a space in which a vacuum is established by the vacuum source. In other embodiments, the method includes the step of irrigating the wound surface by connecting the port to a source of irrigation fluid expelled through the holes onto the wound surface.
Another alternative member is provided including a single stand-off coupled to the wound contacting or wound facing surface of the member. The stand-off includes a plurality of interconnected portions. Illustratively, the stand-off forms a spider-web-like design having a circle portion and a plurality of radial arms extending outwardly from the circle portion. Further illustratively, the stand-off includes an arc portion spaced-apart from and concentric with the circle portion. The radial arms extend through the arc portion. The cross-section of the stand-off is in the shape of a semi-circle having a radius of approximately 1.56 mm. The stand-off defines encompassed regions of the wound facing surface of the member.
Features of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.